In general, the engine room configured to accommodate an engine, a transmission, and the like, is installed at a front side of a vehicle. A variety of components such as an engine installed in an engine room radiate heat in the course of operations. An air passage is formed at a front side of the engine room so as to properly cool the heat with the aid of the input of external air. However, it needs to block the engine room from the outside by closing the air passage so as to prevent excessive cooling of the engine room during the freezing season like the winter, and it also needs to open the air passage during the summer so as to prevent the temperature of the engine room from excessively going up. For this reason, an air flap device configured to open or close the air passage is provided in the vehicle.
The air flap device for a vehicle is installed at the backside of a grill so as to improve the aerodynamic performance and fuel efficiency of the vehicle. The air flap device for a vehicle is a device for controlling the opening and closing of air which is inputted inside of the vehicle in such a way to drive the flap. The air flap device for a vehicle determines whether or not the flap is opened based on the received cooling condition of the vehicle and enables the flap to rotate by driving an actuator to drive a loader and a link connected to the actuator to thereby open or close the air passage. The air flap device for a vehicle includes a plurality of flaps which are rotatably installed to open or close the air passage of a housing, a link which interconnects the plurality of the flaps for rotating the flaps together, and an actuator which provides rotational driving force to the link.
However the conventional air flap device for a vehicle is constituted such that a flap surface and a rotary shaft configured to rotate the flap are formed on a plane, respectively, so that the distance between a buffer surface with a curved surface and the flap surface gradually widens toward the direction of the center. As a result, such a structure causes a problem wherein the amount of the stranded air increases under the situation wherein the air passing through the bumper grill is no longer inputted into the engine room because the flaps are closed, to thereby greatly decrease the effects of improving aerodynamic performance and fuel efficiency.
Meanwhile, as one example of the air flap device for a vehicle, the Korean Patent Publication No. 10-2014-0033802 describes “an air flap device for a vehicle for opening or closing a front side opening formed at the vehicle and a failure determining method for determining the failure thereof”.